1. Field of the Invention
The present invention concerns a device for mounting a cursor movement control device in an electronic system such as computer and, more specifically, to a device for mounting a touch pad device in a portable computer.
2. Background Art
Various electromechanical devices are known in the art for effecting the movement of a cursor on a display device using control signals. For example, so-called "joy-sticks" are frequently used with computing equipment to move a cursor, or another image, that is displayed on the face of the display device. A typical joy-stick operates by producing control signals by means of electrical potentiometers linked to the movable actuating rod where the magnitude of the signal determines the rate of motion and the polarity of the signal determines the direction of cursor movement. Another well known device is the so-called "track ball". The track ball has a spherical member is mounted in a socket that allows the spherical member to rotate about any axis. By rotating the track ball control signals are generated that direct the motion of a cursor, or another image, along the face of a display device. Similar to the track ball is the so-called "mouse" that has a spherical member covered by a palm-sized housing. By pushing the palm-sized housing along a supporting surface the spherical member is rotated and signals are sent to the computer that control the motion of a cursor, or another image, along the face of a display device.
More recently developed than the above devices is the "touch pad". The touch pad allows a user to manipulate the position of a cursor, or another image, along the face of a display device by sliding a finger over the surface of the touch-pad. The touch pad can be made using a printed circuit board that has a pattern of conductors formed in a grid, using a predetermined spacing, that may is juxtaposed with a flexible plastic insulating layer having a pattern of metallization on the under surface. By depressing the flexible layer against the underlying printed circuit grid, signals are produced that are directly related to the particular point on the pad that is being touched.
A touch pad may be designed with several buttons that function similarly to the right and left buttons of a mouse. In the process of mounting a touch pad onto the housing of a portable computer, the touch pad plate is placed against the plastic housing and covered by a plastic mounting case. To protect the touch pad from electromagnetic interference it is necessary to plate the plastic case prior to using the plastic case to support the touch pad plate. The plating process, however, generates contaminants and can adversely affect the workers in the manufacturing facility where the touch pad device is produced. In addition, the use of the plastic mounting case, in addition to the plated metal, increases the weight of the portable computer and causes the thickness of the touch pad unit to be increased, thus restricting the design flexibility of the portable computer.
As such, I believe that it may be possible to improve on the contemporary art by providing a touch pad mounting device that does not require a plating process, that eliminates the use of a plastic case to support the touch pad device, that reduces the thickness of the touch pad unit, that increases the safety of workers in facilities that assemble the touch pads, and that reduces the weight of electrical systems that use the touch pad mounting device.